| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an add/drop module in low-cost and simple configuration in comparison with a conventional module. <P>SOLUTION: The add/drop module comprises a circulator 220 for outputting optical signals from a first port to a second port and from the second port to a third port, an optical multiplexer/demultiplexer 230 which is linked with the second port of the circulator 220, and a number of add/drop parts 240, 250 and the like, and each of the add/drop parts is composed of a circulator 241 for outputting channels from a second port to a third port and from a first port to the second port, and an optical switch 242 wherein a first port is linked with the third port of the second circulator, the third port is linked with the first port of the second circulator, the first port and the third port are switch-linked for passing channels, the first port and a fourth port are switch-linked for dropping the channels, and a second port and the third port are switch-linked for adding the channels. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
